Monolayers of endothelial cells respond to physical denudation with a
characteristic sequence of lamellipodia extrusion, cell migration, and
cell proliferation. Basic fibroblast growth factor (bFGF) has been im
plicated as a necessary component of this process: addition of exogeno
us bFGF enhances monolayer regeneration both in vitro and in vivo, and
monolayer regeneration can be inhibited in vitro by treatment with ne
utralizing antibodies raised against bFGF. Centrosome reorientation fr
om a random location to one preferentially situated between the nucleu
s and the denudation edge has been postulated as a mechanism essential
for cell polarization and subsequent migration. This present study ex
amined the effects of a polyclonal antibody to bFGF and suramin on mon
olayer regeneration, actin microfilament staining, and centrosome orie
ntation at the wound edge of partially denuded bovine large vessel end
othelial monolayers. Treatment with anti-bFGF or suramin abolished mon
olayer repair in these cultures. Cells at the denudation edge showed a
ltered actin staining patterns and reduced lamellipodia extrusion, and
there was complete inhibition of centrosome reorientation in treated
cultures. Monolayer repair and centrosome reorientation could be resto
red by addition of exogenous bFGF in antibody but not suramin treated
cultures. Recent evidence suggests that preferential centrosome locati
on in migrating cells may be a consequence of lamellipodia protrusion
and cell spreading, rather than an indication of cell polarization. Ho
wever, these results indicate that agents which interfere with bFGF av
ailability prevent endothelial monolayer regeneration via mechanisms i
nvolving cell spreading and/or centrosome reorientation. (C) 1993 Wile
y-Liss, Inc.